Abstract:
The aim of this study was to prepare and characterize a hydrogel samples based on Acacia seyal var seyal gum cross-linked with succinic acid. The samples were prepared using varying concentrations of the succinic acid (crosslinker), heating temperatures (130, 140 and 150 ˚C) and heating times (5, 15 and 20 minutes).
The gel content, FTIR, water uptake and the variation of the swelling behavior of the hydrogel samples at different PH were studied. The results of the gel content demonstrated that the main factors which influence the crosslinking efficiency the heating time and temperature. The highest gel content was found for sample S17 (86.4%) whereas the lowest was obtained for S13 (13. 57%). S25 was found to have the highest water holding capacity (1555%). Minor changes between the hydrogel and the crude gum were noticed in the FTIR, in the range 1700 to 1750 cm-1 which is attributed to the characteristic carboxyl group stretching vibration derived from succinic acid cross-links.
The variation of swelling behavior with pH demonstrated high dependency of the hydrogel water holding capacity, on PH, sample S25 showed the highest water holding capacity at pH7.
